… The position in moral philosophy that I find least unsatisfactory is that there exist natural rights, that they can be described in terms of entitlements, and that to be entitled… The rules of original entitlement and transfer that I find plausible correspond fairly closely to the laws of a pure free market society… the “coincidence” reflects some underlying connection between natural rights and utilitarian arguments…

… economic efficiency, due to Pareto, is that a Pareto-improvement is a change that benefits someone and injures no one and a situation is efficient if it cannot be Pareto-improved… I therefore prefer to use a slightly different approach, due to Marshall. I define an improvement as a change such that the total benefit to the gainers, measured by the sum of the numbers of dollars each would, if necessary, pay for the benefit, is larger than the total loss to the losers, similarly measured…

… Suppose there were a situation that was Pareto efficient (could not be Pareto improved) but not Marshall efficient. There would then be a possible Marshall improvement–a change that would benefit the gainers by more, measured in dollars, than it would injure the losers. A bureaucrat god could make that change and simultaneously transfer from gainers to losers a sum larger than the losses and less than the gains, taxing each gainer…

… What justification can there be for making interpersonal utility comparisons in a way that, by comparing gains and losses as measured in dollars, implicitly assumes that the utility of a dollar is the same to everyone? Marshall’s answer was that for most economic questions it does not much matter how you weight utilities. Most issues involve large and diverse groups of gainers and losers…

… more is known about economics than about moral philosophy, so we are more likely to reach true conclusions and be able to convince others of them through the former than through the latter… If I am right, then political disagreement is fundamentally a disagreement about the economic question…

… there is no adequate theory of government behavior that implies that government would choose to do the right… although we do not have an economic theory of the political process as well worked out and broadly accepted as the theory of private markets, we do have enough of such a theory to have some idea of where and why the political market is likely to produce less efficient outcomes than the private market… there exists a large and growing body of empirical studies of the effects of government regulation…

… To take a trivial example, most of our objectives require that we eat occasionally, so as not to die of hunger (exception–if my objective is to be fertilizer). Whether or not people have deduced this fact by logical analysis, those who do not choose to eat are not around to have their behavior analyzed by economists. More generally, evolution may produce people (and other animals) who act rationally…

Oppure, a furia di batterci la testa uno impara:

… The same result may be produced by a process of trial and error. If you walk to work every day you may by experiment find the shortest route, even if you do not know enough geometry to calculate it…

… the idea that economists assume that “all anyone is interested in is money.” Put in that way the assertion is wrong; economists usually assume that people desire money only as a means to other objectives. What is true is that although economics can, in principle, take account of the full richness of human objectives, it is necessary for many practical purposes to assume away all save the most obvious–the consumption of goods, leisure, security, and the like…

… Suppose we know someone’s objective, and also know that half the time he correctly figures out how to achieve it and half the time he acts at random. Since there is usually only one right way of doing things (or perhaps a few) but very many wrong ways, the rational behavior can be predicted but the irrational behavior cannot. If we predict his behavior on the assumption that he is always rational we will be right half the time; if we assume he is irrational we will almost never be right… We are better off assuming he is rational… it takes a theory to beat a theory; until some better alternative is found, rationality is the best we have…

C’è chi propone di sostituire il “buon senso” all’ homo economicus:

… but when it comes to analyzing a market–a complicated interacting system–” common sense” turns out in practice to mean a poorly thought out, inconsistent, and untested theory…

… A second set of objections to the market and the economic approach is based on the claim that neither gives proper consideration to the implications of income inequality… the market–and the criterion of efficiency according to which its outcome is often judged–measures individual values in dollars, not in intensity of feeling… This is equivalent to doing an interpersonal utility comparison on the assumption that the marginal utility of a dollar is the same for everyone…

Qui si puo’ far rilevare che:

… Most of the decisions an economist is interested in affect large and heterogeneous groups of people… differences among individuals can be expected to average out when we consider the effect on the whole group…

… The standard argument for redistribution begins with the claim that, for a given individual, the marginal utility of income declines as income increases. This seems plausible in terms of introspection… The next step is to claim that, absent information about differences in individual utility functions, we must treat each individual utility function as a random draw from the same population, so declining marginal utility of income applies not only to the same individual with different incomes but (on average) to different individuals… It is quite implausible if differing income is the result of differing effort. An individual who greatly values the things that money buys will be more willing than others to give up other goods, such as leisure, in order to get income, so he will, on average, end up with a higher income…